amazon-web-services - 如何在代码构建中将命令的输出分配给变量

Question

每当推送到我的源代码并将 docker 镜像移动到 ECR(EC2 容器注册表)时，我都会尝试构建一个 docker 镜像。

我已尝试使用以下构建规范文件

    version: 0.2
env:
  variables:
    IMG: "app"
    REPO: "<<zzzzzzzz>>.dkr.ecr.us-east-1.amazonaws.com/app"      
phases:
  pre_build:
    commands:
      - echo Logging in to Amazon ECR...
      - aws ecr get-login --region us-east-1
      - TAG=echo $CODEBUILD_RESOLVED_SOURCE_VERSION | head -c 8
  build:
    commands:
      - echo $TAG
      - docker build -t $IMG:$TAG .
      - docker tag $IMG:$TAG $REPO:$TAG 
  post_build:
    commands:
      - docker push $REPO:$TAG
      - printf Image":"%s:%s" $REPO $TAG > build.json
artifacts:
  files: build.json
  discard-paths: yes

当我构建它时，我在 docker build -t 收到错误 invalid reference format

我查看了文档，没有找到任何帮助。

Answer 1

TAG=$(echo $CODEBUILD_RESOLVED_SOURCE_VERSION | head -c 8)

你可以使用 $()

version: 0.2

phases:
  install:
    commands:
      - echo Entered the install phase...
      - TAG=$(echo "This is test")
  pre_build:
    commands:
      - echo $TAG
  build:
    commands:
      - echo Entered the build phase...
      - echo Build started on $TAG

日志:

[Container] 2018/03/17 16:15:31 Running command TAG=$(echo "This is test")
[Container] 2018/03/17 16:15:31 Entering phase PRE_BUILD
[Container] 2018/03/17 16:15:31 Running command echo $TAG
This is test